


Shackled to Humanity

by Judgement



Category: Fate/Grand Order, Fate/stay night & Related Fandoms, Fate/stay night - All Media Types
Genre: Alternate Universe, Angst and Tragedy, F/M, Pining, Reader-Insert, Servant Reader
Language: English
Status: In-Progress
Published: 2020-11-16
Updated: 2020-11-16
Packaged: 2021-03-10 01:22:03
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 1,649
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27585370
Author URL: https://archiveofourown.org/users/Judgement/pseuds/Judgement
Summary: According to history, you saved humanity and then burnt it down. They called you the ten-year tyrant for the decade you terrorized humanity before it fell apart and got pruned like the other failed timelines. Now you were summoned and being asked to save it again. How ironic.
Relationships: Cú Chulainn Alter | Berserker & Reader, Other Relationship Tags to Be Added
Comments: 6
Kudos: 48





	1. Summoning

_“You asked for this! I did everything! Every-fucking-thing you all asked of me! I saved you, I stopped our world from being pruned and when you told me to jump I asked how high. Everything was for the sake of survival—so why?”_

_Ah._ The memory burned in your chest, clawed at your ribcage and threatened to burst. Fate was cruel as she always was, but her humor was sick. You stepped forward out of the smoke and away from the summoning circle. The staff felt heavy in your hand but also like another part of you, an extension. With a flick of your wrist the smoke that had gathered from the summoning machine whisked away at the force.

You lifted your gaze from the ground and met the surprised expression of familiar faces. People you knew in your timeline at one point, some who probably even remembered you. Such was fate’s sick sense of humor, and you heaved a heavy sigh. The command seal tattooed against your skin crackled with energy, barely restrained.

“… How ironic. Though I suppose introductions are in order, hm?”

You set the butt of your staff on the ground and wrapped your elbow around it. Gripped it at the neck and leaned your weight into it.

“You may call me.. Kuro. Avenger. I am the one who saved humanity and then devoured it and watched it burn. So I ask you, Chaldean Master, are you fit to save humanity from your servant?”

With a sick sense of satisfaction, you watched the expressions that flashed across Fujimaru Ritsuka’s face. He recognized you and for a split second there was relief before it was awash with horror. So many questions on the tip of his tongue because he knew you, so how did you end up a servant? He opened and closed his mouth, wracked his brain for the words and you waited patiently.

Finally Ritsuka seemed to gather himself and inhaled only for the King beside him to storm forward. Overcome with a mix of shock and grief,

“You—!” The King grabbed the front of your shirt and yanked you forward. His face was flush and he grit and bared his teeth at you in his displeasure. He yanked you close, looked ready to fight but the anger that boiled behind those red eyes faded away. Grief instantly took its place and his voice stooped low. “—What did you do?! Why? Why did you send me away?” He could have helped!

You smiled up at him, and bitter rage burned to life through your veins. The namesake of your class fueled the fire in you, something that would never go away. They etched you in history as the one who saved it and burnt it all down, they would never remember you as a hero.

“And ask you to burn everything you saved?”

His eyes widened and his hand on your shirt went slack as he searched your face. Looked for any trace of a lie that you wouldn’t—that you didn’t do what you implied.

“I sent you away because you were the one who guided humanity. I think you would have fought me if you knew what I was about to do.”

You grabbed his hand, and he flinched at the strength behind your vice grip. When he let go, you let go of him and dusted off the front of your shirt. He stared at you and tried to process your words, but found he was failing. The two of you went through so much together, you came out on top, so what happened? Why were you a servant and an _avenger_ at that?

Stepping around him you graced your new master with a smile that didn’t reach your eyes then tilted your head back to address the dumbstruck King.

“I’ll spare you the sob story. Ten years of terror later I killed almost everyone and burnt the rest to the ground, and like everything that is a failed timeline—it was pruned.”

Gilgamesh listened to the sound of your fading footsteps until the door to the summoning room slid open and shut. Leaving him and his master who glanced to the door then back to him, uncertain.

“King?” Ritsuka whispered in question.

Gil could feel the sting of anger and pain so hot it burned against his eyes. He would never admit to the tears that dripped down his face. Why? Why you, of all people?

“Leave.” He ordered, he would answer another time.

For now, he mourned you and who you used to be.


	2. Feral [Cú Chulainn Alter]

**Summary for the Chapter:**

> After he stared you down for a long moment, he bared his teeth like the rabid dog you called him and snarled. The action made you laugh before you bared your teeth in kind and did your best to growl.

**Notes for the Chapter:**

> It's late and I'm tired. Apologies for the typos or general ooc-ness.

If there was one person you got close to during your time as a tyrant, it was Cú Chulainn Alter. The berserker didn’t judge you for what you did. You were King, there was a fight to win and a field to do it on so he was happy. You didn’t expect much from him outside his willingness to fight, but surprisingly he sought your company more and more. You briefly wondered if it was because of your slow descent into madness or because you were on the field more than not. Though the claim to madness held little weight in it all, you knew what you were doing at the time with calculating and cold precision. They should have left you alone, you would have faded into obscurity probably, but they didn’t. They deserved your wrath.

Or maybe you were mad.

You sat lazily on the counter in the recreation room. Though surprised and a bit disturbed by your appearance as a servant, most wisely kept their mouth shut. They welcomed you as they did all servants and accepted things as they were. Some things were just better left unsaid, and you really didn’t care if anyone asked or not. Your timeline didn’t exist anymore, and during your war there wasn’t time to write up new history books. You never ended up in the history books because nobody ended up living through it. It was enough that most servants didn’t want to know; it was easier to work with you when they didn’t.

But Cú Chulainn Alter ended up being the support you never knew you needed. The berserker was human, but he ended up with the nose of a bloodhound. The moment he returned, he stilled and dismissed everyone who greeted him upon return as he stalked down the hall. His pace picked up until he was all but looking like the mad berserker he was as he sprinted down the hall. Several of the staff screamed and fled in any direction that he wasn’t heading, causing quite the commotion.

Dread filled up Ritsuka’s chest at the thought of having to fight the berserker a second time. The first time he did it, he scrapped by just barely and on a fluke, no less. He may be stronger now, but so was the berserker. His command seals likely wouldn’t hold him, either. But he was the master, and he had to do something, so with that in mind fueling his fearful steps, he took after his servant.

Cú Chulainn knew you no matter what you came to him as. A servant, a demon—whatever it was, the berserker was so familiar with you; it felt foreign that you weren’t by his side. Your scent struck lightning in him and the manic grin ate away at his face as he rushed down the hall until he hit the recreation room. His red eyes narrowed in on your lone figure on the counter and he tore over to you. His tail wrapped around your waist and hefted you into the air, holding your form above him as he grinned.

True to the relationship he had with you, there wasn’t an ounce of fear in your eyes as you stared down at him, unimpressed. After he stared you down for a long moment, he bared his teeth like the rabid dog you called him and snarled. The action made you laugh before you bared your teeth in kind and did your best to growl. You remembered stupidly practicing this with him for hours, back when you were alive. When you returned his greeting, he looked oddly pleased if he was even capable of such a thing.

“Cú.” You greeted.

“Master.” He replied.

You snorted, “I’m not your master anymore.”

There were few that could match the terror you stuck in people during the ten plus years he served at your side. He wouldn’t call it love, he didn’t know the word or the meaning but there was something about you. He didn’t want to kill you; he itched to fight you like he did anybody, but he wanted to.. keep you. Like he kept Gáe Bolg. You were a weapon of mass destruction if you wished it, and even more now that you were a servant.

He didn’t respond to your comment, though. Instead, he pulled you in, brought your face close to his as he eyed you and the subtle changes. Then, unexpectedly, he pressed his cheek against yours and nuzzled you to him. If he was a cat, you were positive he would’ve purred. It stunned the entire room into silence as they watched the scene unfold.

When Ritsuka finally caught up, he’s surprised as everyone else was to find you sitting on the berserker’s shoulder. The Chaldean master could count on one hand the amount of times he saw Cú as content as he was right there. Which was to say this was the first time. When you placed your arm on top of his head to prop your chin up in your hand, he growled, but you rolled your eyes.

“Be quiet, rabid dogs don’t get to complain when you're the one who won’t let me down.”

He grunted in response. Instead of throwing you off his shoulder his hand held you tighter.


End file.
